Musical instruments too, galore. Some had no frets - that way no one can tell you you're playing the wrong chords, I heard a fretless-guitar player say once - and ukuleles proliferated, including one made from the remodelled remains of a long-dead banjo.
"I call it the Phoenix," said its maker Graham Hurlock, whose Bare Bones Musical Instruments stall was full of distinctively shaped handmade guitars. "It rises from the ashes of an old banjo and the ukulele at the moment is pretty much king."
As Moa's set ends, I seek out festival president Roger Giles, whose splendid white chinstrap beard and straw hat puts me in mind of an Amish farmer. He tells me this is the 41st annual festival - the event began at Labour Weekend 1973 at Moller's Farm and moved to nearby Knock Na Gree in 1980 before ending up at Kumeu in the early '90s.
Giles, who would forgive me for saying he is not in the first flush of youth, says that attendances have remained pretty steady over the years, and he has been particularly cheered by the numbers of young people showing up.
"We were self-taught, most of us," he said, "and as we moved on, we realised that if we'd had some musical education, we would have done better. So a lot of have made sure - I know I have with my kids - made sure they had proper musical lessons and they are good musicians now.
"I think kids are getting fed up with electronic music and when they find they can make their own they get so much more fun out of it."
It may seem a perverse conclusion in the week that computer-driven pop has propelled a young New Zealander to the pinnacle of the music business, but I suspect that Johnny McCauley would agree. The Auckland 21-year-old is still playing the modest guitar his parents bought him when he was a young teenager, but there are adults around, including his parents, who believe in him enough to have bankrolled him into a bit of studio time: the result is an EP called The Bottom Line.
"I come from a Christian family and I grew up with a lot of singing in church," he told me by way of explaining that the appeal of folk music is in his blood. "We did a lot of gospel, but bluegrass and country as well. You sing loud and you sing out of tune but you get better if you keep at it."
It wasn't all performance. As I wandered the laneways between the tents, I kept stumbling on small clusters of people, perhaps rehearsing or just playing together, exchanging words and music, ideas and chord patterns. It seemed fine to eavesdrop, but rude to ask questions.
Then, just when I thought it was safe to leave, I was waylaid by Morris dancers. Andy Smith on a candy-coloured recorder and Henry Falkener on a handsome old Italian-made accordion were making music for their jingle-bell fellow members of the City of Auckland Morris Dancers as they rehearsed a piece called Woodhouse Bog.
There were Welsh and Hungarians and Romanians, too. The latter two were dancers, but there's no dancing without music. And as Louis Armstrong famously remarked, "All music is folk music; I ain't ever heard a horse sing a song."
